Pattern discrimination system using television

ABSTRACT

A pattern discrimination system for automatic and rapid detection of occurrences of an abnormal condition in a pattern under surveillance comprising the means and steps of producing at least one horizontal gate pulse and vertical gate pulse of any required width and position by utilizing the television art, sampling a video signal with the horizontal and vertical gate pulses to form at least one sample surface variable in position, size or shape thereof in the field of view of a monitor, producing an integrated value of voltage of a video signal corresponding to the sample surface of the pattern under surveillance, digitally storing the integrated value of voltage of the video signal in a digital memory, and producing another integrated value of voltage of the video signal corresponding to said sample surface of the pattern under surveillance after a lapse of a predetermined time interval and comparing the second integrated value of voltage with the integrated value of voltage stored previously.

' United States Patent 1191 Takahashi Sept. 17, 1974 [5 PATTERNDISCRIMINATION SYSTEM 3,781,468 12/1973 Chomet l78/6.8

USING TELEVISION E H d w B Primary xaminerowar ritton [75] Inventoryasaakl Takahashl Yokohama Attorney, Agent, or FirmStevens., Davis,Miller &

apan Mosher [73] Assignee: n a c Incorporated, Tokyo, Japan 22 Filed:Sept. 11, 1972 [57] AFSTRACT A pattern discrimination system forautomatlc and PP N05 287,733 rapid detection of occurrences of anabnormal condition in a pattern under surveillance comprising the [30]Foreign Application Priority Data means and steps of producing at leastone horizontal Dec 9 1971 Ja an 46 99O08 gate pulse and vertical gatepulse of any required Jan 20 1972 Ja an W723i; width and position byutilizing the television art, sam- 4 1972 Japan 43727 pling a videosignal with the horizontal and vertical y p gate pulses to form at leastone sample surface vari- [52] U S Cl 178/618 178/1316 33 l78/DIG 38 ablein position, size or shape thereof in the field of [51] H04 /18 view ofa monitor, producing an integrated value of [58] Field DIG 38 voltage ofa video signal corresponding to the sample 1 G surface of the patternunder surveillance, digitally storing the integrated value of voltage ofthe video sig- [56] References Cited nal in a digital memory, andproducing another integrated value of voltage of the video signalcorrespond- UNITED STATES PATENTS ing to said sample surface of thepattern under surveil- 2,244,826 10/1941 Cox l78/DIG, 1 lance after alapse of a predetermined time interval 3,562,423 2/1971 Murphy 178mm- 33and comparing the second integrated value of voltage gT with theintegrated value of voltage stored previously. 3:743:768 7/1973coplaiitiiii: .1: 178/110: 38 2 Claims, 8 Drawing Figures A o 5 s c f VIis- L Q m E e V 1 m w, L v

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f H 3 54 4 s 5 PATTERN DISCRIMINATION SYSTEM USING TELEVISION Thisinvention relates to improvements in pattern discrimination systemsusing the television art.

The practice of using a television system comprising at least onetelevision camera and at least one minitor for keeping watch on variousconditions (for protecting safes, detecting unwarranted intruders,keeping vigil against burglars, detecting fires and effecting control oftraffic conditions, for example) has in recent years become verypopular. However, this system has the disadvantage that an operator isrequired to watch one or more monitors at all times. It is a strain onthe operator to constantly watch, particularly at night, a plurality ofminitors and this entails an increase in the number of operatorsrequired for this task and hence a rise in personal expenses.

To solve this problem, proposals have been made to employ a surveillanceapparatus which uses atelevision system and produces an alarm only whenan abnormal condition is detected. By this arrangement, it is possibleto save labor because the operator has to look at a minitor only when analarm is given for an accident or to take a picture or keep a record ona video tape recorder of the abnormal condition upon production of asignal indicatingthe trouble without requiring the operator.

Generally, the use of a digital system for discrimination of informationon a pattern under surveillance entails the use of an enormous number ofbits for covering every nook and corner of the pattern. At the presentstatus of art, the surveillance apparatus of the type described usesvery expensive video discs, memories and other components. Thus, fullrealization of advantages from use of the surveillance apparatus of thetype described has been hampered by inability to produce an apparatuswhich is low in cost and reliable in performance. In addition to beinguneconomincal, the use of a digital system designed to compare videosignals for the whole pattern has an additional disadvantage in thatfatal trouble occurs when comparison of information on the pattern iseffected with respect to the entire field of view of the monitor assubsequently to be described.

The present invention obviates the aforementioned disadvantages of theprior art. Accordingly, the invention has as its object the provision ofa patterndiscrimination system using a television system whereina num:ber of horizontal gate pulses and vertical gate pulses corresponding toportions of a pattern to be sampled are produced. A video signal of thepattern produced by a television camerais sampled by the horizontal andvertical gate pulses in order. to produce a signal or signalsrepresenting a sample portion or portions of the pattern, voltage orvoltages of an integrated value of said signal or integrated values ofsaid signals for one field being supplied to a digital memory as a pieceof information for the pattern under surveillance, and such piece ofinformation for the one pattern under surveillance being compared withthe information of the pattern stored in the digital memory, so thatpattern discrimination can be effected rapidly and automatically.

One feature of the invention lies in the fact that comparison ofinformation is made not between video signals for the whole patternunder surveillance but between components of the video signals fordiscrete portions of the pattern under surveillance of any size, shape,position and number obtained by sampling. The integrated value of thevoltage for one field period for each of these discrete portions orsample surfaces is compared with the corresponding integrated value ofthe voltage for one field which is obtained earlier at a predeterminedtime interval and stored in the digital memory.

The reasons why the aforementioned specific portion or portions of thefield of view of the television camera which may be of any number, size,shape and position are used as sample surfaces are as follows: If thepattern discrimination system used as a burglar-proof device for thepaintings shownin FIG. 6, for example, is designed to cover the entirefield of view of the television camera or the minitor, the movement of aperson in the field of view would be detected by the system as anabnormal condition even if the paintings are not involved in anaccident. If a sample surface or surfaces of suitable number, shape,size and position are selected which consists of relevant portions ofthe paintings, the aforementioned disadvantage could be obviated and theaccident involving the paintings could only be detected as an abnormalcondition. The gate pulses produced correspond in position, size, shapeand number to the sample surfaces on the field of view of the monitor.

When optical images of a pattern illuminated by a light source areconverted into electric signals by a television camera, the intensity ofillumination may undergo a gradual change caused by a change in weatheror the light source and such change may be detected as an abnormalcondition in the pattern discrimination system according to thisinvention. However, this can be obviated by replacing at regularintervals the information stored in the memory by new information.Replacements of the stored information also have the effect ofpreventing the system from passing the judgement of the existence of anabnormal condition by error due to drift which may be encountered in thetelevision circuit.

The pattern discrimination system according to this invention alsopermits the number of objects passing through the field of view of themonitor to be determined by counting the number of occurrences of theabnormal conditions in the sample surfaces obtained in comparison withthe normal conditions stored in the digital memory.

Additional and other objects, as well as features and advantages of theinvention, will become evident from the description set forthhereinafter when considered in conjunction with the accompanyingdrawings, in which:

FIG. 1 shows the basic concept of the present invention, showing apattern and sample surfaces thereof, and vertical and horizontal gatepulses in relation to a video signal;

FIG. 2 isa block diagram of an apparatus used for carrying out thesystem according to this invention into practice;

FIG. 3A is a diagrammatic representation of one form of the vertical andhorizontal gate pulse producing circuit used in the system according tothis invention;

FIG. 3B shows the vertical and horizontal gate pulses;

scribed with reference to FIG. 1. When optical images of a pattern D areconverted into electric signals by means of a television camera, thepattern D appears in a field of view A of a monitor. B designateshorizontal gate pulses and C, vertical gate pulses. If a video signal Swhich corresponds to the monitor field of view A is sampled by thehorizontal gate pulses and vertical gate pulses, a signal or signalscorresponding in number to the sample surfaces of pattern D can beproduced. Each of the signals representing the sample surfaces ofpattern D may, for example, be integrated for one field period.

The sample surfaces, 1, 2, 9 appearing in the monitor field of view Ashown in FIG. 1 correspond to the signals produced by sampling the videosignal of the pattern D by the horizontal gate pulses and vertical gatepulses B and C. In actual practice, outputs of a gate pulse generator 10shown in FIG. 2, adapted to produce horizontal gate pulses with verticalgate pulses, are taken out through a line 23 and mixed with the videosignal S, so that the sample surfaces 1, 2, 9 are superimposed on thepattern D in the monitor field of view A and can be seen as shown inFIG. 1 with respect to their position, size, shape and number. Thisfacilitates setting of the position, size, shape and number of thesample surfaces.

The image actually seen in the monitor field of view A as shown in FIG.1 consists of the sample surfaces 1, 2, 9 and the pattern D. Otherportions shown in FIG. 1 are inserted in FIG. 1 merely for the sake ofconvenience to enable the invention to be clearly understood and are notactually visible in the monitor field of view A.

Production of gate pulses will be described with reference to FIGS. 3Aand 3B. In FIG. 3A, h designates horizontal drive pulses. 30 designatesa differentiation circuit which differentiates each of the pulses h andtriggers a one-shot multivibrator 31 by a differentiated pulsecorresponding to the trailing edge of the pulse h as shown in FIG. 38 tocause the latter to produce a pulse j. The pulse width t may be variedby a variable resistor 34.

The pulse j is differentiated by differentiation circuit 32, and aone-shot multivibrator 33 is triggered by a differentiated pulsecorresponding to the trailing edge of pulse j and caused to produce apulse k. The pulse width t may be varied by a variable resistor 35.

Gate pulses II are reversed in form with respect to pulses k andcorrespond to the horizontal gate pulses I-I shown in FIG. 1. Thehorizontal drive pulses h shown in FIG. 38 have a horizontal scanningperiod of T corresponding to the width of the monitor field of view A.

It will be seen that the horizontal position of gate pulses H, can bechanged by varying pulse width t by means of variable resistor 34 andthat the width of gate pulses H, can be changed by varying pulse width tby means of variable resistor 35. This also applies to the vertical gatepulses. In FIG. 3A, and 42 are differentiation circuits, 41 and 43 areone-shot multivibrators, and 44 and 45 are variable resistors capable ofadjusting the width of vertical gate pulses. l designates vertical drivepulses. The gate pulses V shown in FIG. 1 can be produced by invertingpulses n shown in FIG. 3B. Pulses m shown in FIG. 3B are produced byone-shot multivibrator 41.

Gate pulses k and n are of reversed polarity and are mixed by a polarityreversing and mixer circuit 46 to produce gate pulses H and V shown inFIG. I which are taken out through a terminal 47. The sample surface 1shown in FIG. I is formed by a pair of one horizontal gate pulse and onevertical gate pulse H and V Thus, it will be appreciated that the samplesurface 1 may be disposed in any position and may have any shape andsize as desired in the monitor field of view A.

The gate pulse generator 10 shown in FIG. 2 comprises circuits forproducing the abovementioned gate pulses which may be in any number asrequired. In the embodiment shown and described, there are provided sixgate pulse producing circuits for H H H and V,, V V which are combinedwith one another for V,I-I,, V I-I VIH3, V2H1, VzHg, V2H3, V3H1, V3H2and V3H3 which correspond to nine sample surfaces 1, 2, 9. Gate pulse Vfor example, is concerned with the simultaneous formation of samplesurfaces 1, 2 and 3, so that a variation in the position and width ofgate pulse V simultaneously affects sample surfaces 1, 2 and 3. Thus, ifit is desired to cause a variation to occur in each of the samplesurfaces independently of one another, it would be necessary to provideeighteen gate pulse producing circuits.

There are a number of gate pulse producing systems which can be used inthis invention. The gate pulse producing system used in this embodimentis one which uses one-shot multivibrators to produce nine samplesurfaces.

A video signal corresponding to a line E in the monitor field of view Ais indicated by F in FIG. I. Signals on sample surfaces 4, 5 and 6 havewave forms a, b and c in video signal F respectively. In a video signalG, d is a composite signal for sample surfaces 7, 8 and 9, e is acomposite signal for sample surfaces 4, 5 and 6 and f is a compositesignal for sample surfaces 1, 2 and 3. Thus, it is possible to take outthe component of a video signal corresponding to the sample surface 1 byusing gate pulses V I-I the component of the video signal correspondingto the sample surface 2 by using gate pulses V H and so on so that thecomponents of the video signal corresponding to sample surfaces 3 to 9can be taken out by using gate pulses V 1-1 to V H FIG. 2 shows one formof the apparatus used for carrying out the system according to thisinvention into practice. The video signal S is supplied to video signalamplifying, integrating and gating circuits AG to AG On the other hand,gate pulses V I-I V H V I-I V I-I VgHg, V2H3, V3H1, VQHQ and V3H3 aretaken Out from the gate pulse generator 10 described with reference toFIG. 3A and supplied to circuits AG to AC FIG. 4 shows one of the videosignal amplifying, integrating and gating circuits shown in FIG. 2.Video signal S is supplied to a video signal amplifier circuit 50 andamplified thereby. The amplified video signal is introduced into asampling and holding circuit 51 performing the operation of integrationto which the aforementioned gate pulses H,, V, are supplied through aline 52, so that the portion of the video signal S corresponding to thesample surface 1 is sampled. More specifically, the integrated value ofthe voltage for one field period corresponding to the sample surface 1is produced and stored as a signal for the sample surface 1. At the sametime, circuit 51 is reset after a lapse of one field period by a resetpulse produced by a blanking signal supplied through a line 53. Thus,circuit 51 is ready for integrating the next following input thereto.

In this way, the video signal S supplied to video signal amplifying,integrating and gating circuits AG, to AG is amplified and sampled sothat the integrated values of the voltages for one field periodcorresponding to sample surfaces 1 to 9 are produced and stored whilethe gating circuits are reset by reset pulses after the lapse of onefield period. This cycle of operation is repeated. GT, in FIG. 4 is thesame gate GT, shown in FIG. 2, and 54 designates a line through which aclock pulse is supplied to the gate GT,.

Thus, the integrated value of the voltage for one field periodcorresponding to the video signal for the sample surface 1 shown in FIG.1 is stored in the video signal amplifying, integrating and gatingcircuit AG, shown in FIG. 2. In like manner, the integrated values ofthe voltages for one field period corresponding to the video signal forsample surfaces 2 to 9 shown in FIG. 1 are stored inthe video signalamplifying, integrating and gating circuits AG to A6,, respectively.Gate pulse generator 10 is connected through a line to a synchronizingsignal generator (not shown) so that the gate pulses may be produced insynchronism with the video signal S.

The output signal voltages of circuits AG, to AG are supplied to gatesGT, to GT respectively. Gates GT, to GT,, successively effect gatingupon receiving a supply of clock pulses from a clock pulse generator 11, and the outputs of gates GT, to GT are successively converted intodigital values by an analogue-to-digital converter 12. At the same time,gates GT, to GT are successively made to effect gating by clock pulsessupplied from clock pulse generator 11 to transmit the output of gate GTto a buffer and AND circuit BF,. It will be appreciated that the outputsof integrating and gating circuits AG to AG, are successivelytransmitted through gates GT to GT A-D converter 12 and gates GT,, toGT,,, to buffer and AND circuits BF to BF respectively.

Clock pulse generator 11 shown in FIG. 2 is connected through line 20 tothe synchronizing signal generator (not shown) so that the transmissionof the outputs of gates GT to GT, may be in synchronism with the videosignal S. The nine output signal voltages of integrating and gatingcircuits AG, to AG are succesively converted'into digital quantitieswithin about 1 millisecond in each vertical blanking period by theanalogue-to-digital converter 12.

In this embodiment, the output of analogue-to-digital converter 12 isset at a digital quantity represented by three bits by consideringeconomy and also because this arrangement suits the purpose for whichthe invention is intended. It is to be understood that the invention isnot limited to this digital quantity and that a digital quantityrepresented by a greater number of bits may be used in this invention.The analogue-to-digital converter 12 used in this embodiment is of thesuccessive operation type. It is also to be understood that theinvention is not limited to this type and that nine analogue-to-digitalconverters may be used and arranged in parallel with one another.

The operation of buffer and AND circuits BF, to BF will be describedwith reference to circuit BF, shown in FIG. 5 which comprises a firstbuffer 60 and a second buffer 62 (which are buffers of three bits asaforementioned), an AND circuit 63 for checking on the digital quantitystored in the two buffers, and a gate circuit 61.

The digital quantity obtained from the output of circuit AG, byanalogue-to-digital converter 12 is invariably stored in the firstbuffer 60 initially. As aforementioned, new digital quantities arestored one after another in the first buffer 60 each for one fieldperiod. For example, if a memory command signal 21 is supplied fromoutside to a scanner 13, then the digital quantity stored in the firstbuffer 60 is transferred by the gating action of gate 61 which isoperated by a pulse producing circuit 69 through a line 65 to the secondbuffer 62. At this time the movable contact of a switch SW is in contactwith the lower fixed contact shown. The digital quantity stored in thesecond buffer 62 shows no change unless the memory command signal 21 issupplied thereto. Thus, the buffer and AND circuit BF, is, in theabsence of the memory command signal 21, in a collation mode in which afresh digital quantity introduced into the first buffer 60 is examinedand compared with the digital quantity stored in the second buffer 62 bythe AND circuit 63 whose output is taken out through a line 64.

Other buffer and AND circuits BF to BF function in the same manner asdescribed with reference to circuit BF,. The outputs of the buffer andAND circuit BF, to BE, are supplied to an ANlD circuit 14 as shown inFIG. 2.

One example of examining and comparing a new digital quantity with thedigital quantity stored in the second buffer 62 will be described withreference to FIG. 6. This example is an application of the invention ina burglar-proof device adapted for use with paintings exhibited in agallery. In the figure, A designates a field of view of the monitor asshown at A in FIG. 1. Paintings 71 to 79 and men 70, 70 correspond tothe pattern D shown in FIG. 1. The paintings 71 to 79 and men 70, 70 areused as nine sample surfaces corresponding to the nine sample surfacesshown in FIG. 1. This device is intended to detect the theft of any oneof the paintings concerned without detecting the movement of men in thegallery.

When there is no abnormal condition involving any one of the ninepaintings, the components of a video signal of normal valuecorresponding to the nine sample surfaces are supplied to video signalamplifying, integrating and gating circuits AG, to AC passedsuccessively through gates GT, to GT,, respectively by clock pulsessupplied successively from clock pulse generator 11, and converted intodigital quantities by analogue-to-digital converter 12 which are storedin the first buffers 60 in buffer and AND circuits BF, to BF,respectively.

If a memory command signal is supplied to the scanner 13, each gate 61of each buffer and AND circuit performs a gating operation so as totransfer the digital quantity stored in the first buffer 60 of eachbuffer and AND circuit to the second buffer 62 thereof.

If no other memory command signal is supplied to the scanner 13 afterone digital quantity transfer operation is performed, then a new digitalquantity supplied as an input to each of the first buffers 60 isexamined and compared with the digital quantity stored previously ineach of the corresponding second buffers 62, and the results aretransferred from all the circuits BF, to BE, to the AND circuit 14. Theoutputs of the AND circuits of the buffer and AND circuits BF, to BFwill indicate agreement of the compared digital quantities and theoutput of the AND circuit 14 will also indicate agreement of thecompared digital quantities, so that an alarm circuit 15 is notactuated.

Assuming that the painting 71 shown in FIG. 6 is stolen, a change willoccur in the component of the video signal corresponding to the samplesurface 1. Thus, the digital quantity supplied to the first buffer 60 inthe buffer and AND circuit BF, after the theft has taken place will varyfrom the digital quantity stored in the second buffer 62 therein. As aresult, a disagreement signal will be produced by the AND circuit 63 andthe AND circuit 14 will also produce a disagreement signal, so that thealarm circuit 15 is actuated to give warning of the theft.

An alarm signal produced by the alarm circuit 15 and taken out through aline 22 shown in FIG. 2 to the outside may be supplied to a photographiccamera or a video tape recorder to keep a record of the scene of thecrime. Alternatively, the line 22 for taking out the alarm signal to theoutside may be connected to an apparatus to transmit the alarm signalthrough communication lines to a remote place.

It is possible to obtain the number of objects that have moved in thefield of view of the monitor by counting the number of alarm signalsproduced by the alarm circuit. Also, it is possible to obtain the numberof alarms given for each sample surface by counting the outputs of eachAND circuit of buffer and AND circuits BF, to BF,,.

Another example of application of this invention is shown in FIG. 7. Asshown, the invention is directed to a burglar-proof device for a jewel80 placed in a showcase. A designates the showcase which corresponds tothe field of view of the monitor, 1, 2, 3, 4 and 5 designate samplesurfaces, the sample surfaces 1,2, 3 and 4 surrounding the jewel 80while the sample surface S is set on the jewel 80.

In case the pattern under surveillance is illuminated by a light, suchas one supplied through a household power supply outlet, whose intensityof illumination remains constant at all times, only one memory commandsignal 21 may be supplied at the beginning of the operation to storeinitial digital quantities in the second buffers 62 in buffer and ANDcircuits BF, to BF and digital quantities successively producedthereafter may be compared with the initially stored digital quantities.If, however, the pattern under surveillance is disposed out of doors andsubjected to illumination which gradually varies in intensity, or if thecircuits of the television camera used are not stable in performance andthe signal voltages produced vary gradually with time, false alarms willbe produced by changes in the signal voltages of sample surfaces due tochanges in the intensity of illumination to which the pattern issubjected or to the instability of the television camera circuits, evenif 'no abnormal condition is produced in the pattern. This problem isobviated in the present invention by using a timer, for example, whichis operative to produce a plurality of memory command signals atintervals of, say, 5 minutes and to supply the same to the scanner 13.By this arrangement, the digital quantitiesstored in the second buffers62 in all the buffer and AND circuits each can be replaced by a newdigital quantity at intervals of 5 minutes.

If there is no appreciable change in the intensity of illumination in 5minutes, there will be no change between the stored information on thepattern and the information on the pattern obtained five minutes later;therefore, no alarm is produced. Thus, it is possible to eliminate thelikelihood of false alarms which might otherwise be produced by changesin the digital quantities of the sample surfaces of the pattern causednot by the abnormal conditions occurring in the pattern but by changesin extraneous conditions not involving the pattern.

The embodiment shown and described above concerns the application of theinvention in cases where one pattern is placed under surveillance at atime in an effort to detect the occurrence of abnormal conditions in it.The invention is not limited to this embodiment and can have applicationin cases where a plurality of patterns are placed under surveillance ata time to detect the occurrences of the abnormal condition in them bystoring the reference information in a plurality of memories.

In these cases, one television camera with a pantilt head may be used ora plurality of television cameras may be utilized for converting theoptical image of a plurality of different patterns into electricsignals. This application will be described with reference to FIG. 5.The movable contact of the switch SW shown in the figure is brought intocontact with an upper fixed contact to connect gate 61 to a gate 66. Ifa signal is supplied through a line 90 to a scanner circuit 68 inscanner 13, then the scanner circuit 68 selects any one of memories M,to M,,,.

Assuming that an optical image of a first image is converted into anelectric signal and memory M, is selected, a gate pulse will be producedby pulse generator 69 and transmitted through line 65 to gates 61 and 66if a memory command signal 21 is supplied to scanner 13. This permitsthe digital quantities of the sample surfaces to be passed on from thefirst buffer to the memory M, through the scanner circuit 68 to bestored therein. The outputs of buffer and AND circuits BF to BF aretaken out through a line 94.

The digital quantity corresponding to each sample surface is representedby three bits, so that it is possible to store in a memory the digitalquantity corresponding to one pattern by using 27 bits altogether sinceone pattern comprises nine sample surfaces. This is conducive toreducing the cost of production of the memories.

When the information on a second pattern is stored in a memory, a signalis supplied through line to the scanner circuit 68 to connect the sameto memory M so that the information on the second pattern is stored inmemory M in like manner. The information on the next following patternsis stored successively in the same manner till the information on atenth pattern is stored in memory M Upon completion of storing of theinformation on the tenth pattern in memory M,,,, the apparatus is placedin a collation mode till another memory command signal 21 is supplied toscanner 13. Now, if the optical image of the first pattern is convertedinto an electric signal again and memory M is selected by the scannercircuit 68 in scanner 13, the information in memory M will be returnedthrough a gate 67 in the scanner 13 to the second buffer 62 in the firstbuffer and AND circuit BF Gate 67 is open in the absence of a memory command signal 21 to permit the information stored in a memory M to bereturned to the second buffer 62 in a buffer and AND circuit. A line 93from the gate 67 in the scanner 13 is one through which information istransferred to the second buffers 62 in buffer and AND circuits BF to BFAll the information represented by twenty-seven bits in memory M istransferred to the second buffers 62 in buffer and AND circuits BF toBE, in this way and compared with the information stored in the firstbuffers 60 therein.

Then, if the optical image of the second pattern is converted into anelectric signal again and memory M is selected by the scanner circuit68, the information stored in the second buffers 62 in the buffer andAND circuits BF to BE, is replaced by the information stored in memory Mand compared with the new information supplied to the first buffers 60therein.

The optical images of the third to tenth patterns are successivelyconverted into electric signals which are processed in the same manneras aforementioned so as to compare the patterns with one another atregular intervals. The AND circuit 14 is actuated in the same mannerwhen ten patterns are placed under surveillance as when one pattern isplaced under surveillance.

Another application of the invention presently to be described alsoinvolves a sort of pattern discrimination. In this application, theinformation on 10 different patterns may, for example, be stored in 10memories M to M respectively, and the information on the pattern D shownin FIG. 1 may be stored in memory M for example. A television camera mayselectively convert the optical image of any one of a plurality ofpatterns including the pattern D as desired into an electric signal tocompare the information on the selected pattern with the informationstored in any one of the memories M, to M If scanner 13 is made to scanmemories M to M at high speed and the information stored therein iscompared with the information on the pattern D while the televisioncamera is converting the optical image of the pattern D into an electricsignal, a coincidence signal should be produced when memory M isscanned. The coincidence signal is produced by the alarm circuit 15shown in FIG. 2 and indication is given at the same time that the memorywhose information coincides with the information on the patternbeingsurveyed is memory M,. A line 91 shown in FIG. 5 is one throughwhich an output signal of the scanner 13 is transmitted to a counter 16to cause the latter to indicate that the memory sought is memory M Aline 92 shown in FIG. 5 is one through which an output signal of counter16 is transmitted to the alarm circuit 15 to give an alarm that thememory sought is memory M All the embodiments of the invention shown anddescribed hereinabove involve the use of the monochrome televisioncamera or cameras and the processing of the video signal 8 produced byconverting the optical image of the pattern D into electric signals. Itis to be understood, however, that the. invention is not limited tothese embodiments and that the invention can have application in caseswhere the pattern D is in color and a color television camera is used toeffect pattern discrimination based on colors. If the optical image ofthe pattern D is converted into an electric signal by using a colortelevision camera when the pattern D is colored, three video signals forred, green and blue colors respectively will be produced in place of onevideo signal which is the case when a monochrome television camera isused. It will thus be necessary to use three sets of the apparatus shownin FIG. 2 and to supply each of the red, green and blue video signals tothe input terminal of one of these three apparatus, and it will bepossible to effect pattern discrimination in color.

Discrimination of a pattern represented in one or more colors may beeffected by using the apparatus shown in FIG. 2 which may agree innumber with the number of color or colors of the pattern.

Discrimination of a color pattern can be effected based on a colorcharacteristic of the pattern by using a monochrome television camera.In this case, various types of color filters are inserted in thetelevision camera and the color of the pattern which is characteristicthereof is only converted into an electric signal for processing.

What is claimed is:

1. A pattern discrimination method for automatic and rapid detection ofoccurrences of an abnormal condition in a plurality of patterns undersurveillance comprising the steps of producing a number of horizontalgate pulses and vertical gate pulses of any width and position asrequired by utilizing the television art, forming in the field of viewof a monitor one or more sample surfaces variable in position, size andshape thereof by sampling by using said horizontal gate pulses andvertical gate pulses, converting optical images of the patterns undersurveillance into electric signals by means of at least one televisioncamera, producing and storing separately in a plurality of memories aplurality of sets of integrated values of voltages of video signalcomponents corresponding to said one or more sample surfaces of thepatterns under surveillance, and producing further plurality of sets ofintegrated values of voltages of video signal components correspondingto said one or more sample surfaces of the patterns under surveillanceand comparing said further plurality of sets of integrated values ofvoltages with the plurality of sets of integrated values of voltagesstored separately in the memories.

2. A pattern discriminating apparatus for automatic detection ofoccurrences of an abnormal condition in a pattern under surveillance,comprising:

generating means for generating horizontal and vertical gate pulses;

sampling means for sequentially sampling first and second portions of avideo signal corresponding to a predetermined portion of the field ofview of a television camera with said horizontal and vertical gatepulses;

integrating means for integrating the sampled video signal portions;

converting means for converting the integrated video signal portionsinto first and second series of corresponding digital pulses;

digital memory means for storing said first series of digital pulsestherein;

comparing means for comparing said stored digital pulses with saidsecond series of digital pulses;

indicator signal means for producing a signal when said stored series ofpulses and said second series of pulses compared in said comparing meansdiffer by a predetermined amount;

a plurality of AND gates, each having one input connected to an outputof said sampling means;

a gate pulse generator connected to a second input of each of said ANDgates, said gate pulse generator generating a plurality of pairs ofvertical and ing means to said indicator signal means.

1. A pattern discrimination method for automatic and rapid detection of occurrences of an abnormal condition in a plurality of patterns under surveillance comprising the steps of producing a number of horizontal gate pulses and vertical gate pulses of any width and position as required by utilizing the television art, forming in the field of view of a monitor one or more sample surfaces variable in position, size and shape thereof by sampling by using said horizontal gate pulses and vertical gate pulses, converting optical images of the patterns under surveillance into electric signals by means of at least one television camera, producing and storing separately in a plurality of memories a plurAlity of sets of integrated values of voltages of video signal components corresponding to said one or more sample surfaces of the patterns under surveillance, and producing further plurality of sets of integrated values of voltages of video signal components corresponding to said one or more sample surfaces of the patterns under surveillance and comparing said further plurality of sets of integrated values of voltages with the plurality of sets of integrated values of voltages stored separately in the memories.
 2. A pattern discriminating apparatus for automatic detection of occurrences of an abnormal condition in a pattern under surveillance, comprising: generating means for generating horizontal and vertical gate pulses; sampling means for sequentially sampling first and second portions of a video signal corresponding to a predetermined portion of the field of view of a television camera with said horizontal and vertical gate pulses; integrating means for integrating the sampled video signal portions; converting means for converting the integrated video signal portions into first and second series of corresponding digital pulses; digital memory means for storing said first series of digital pulses therein; comparing means for comparing said stored digital pulses with said second series of digital pulses; indicator signal means for producing a signal when said stored series of pulses and said second series of pulses compared in said comparing means differ by a predetermined amount; a plurality of AND gates, each having one input connected to an output of said sampling means; a gate pulse generator connected to a second input of each of said AND gates, said gate pulse generator generating a plurality of pairs of vertical and horizontal gate pulses, one pair of gate pulses being supplied to a corresponding one of said AND gates through said second input thereof; means applying outputs of said AND gates sequentially to said integrating means; means applying outputs of said integrating means in a corresponding sequence to a corresponding plurality of digital memory means and comparing means; and means applying outputs of said plurality of comparing means to said indicator signal means. 